Instrument for determining motor vehicle action



Oct. 6, 1953 v L. J. FULLER 2,654,538

INSTRUMENT FOR DETERMINING MOTOR VEHICLE ACTION Filed June 3, 1952 2Sheets-Sheet l i w n m g Q y rn @o n, .P w

n llno Oct. 6, 1953 1 J. FULLER 2,654,538 INSTRUMENT ROR DRTERNININGMOTOR VEHICLE ACTION Filed June 3, 1952 2 Sheets-Sheet 2 OU/S J. RME/RPatented Oct. 6, 1953 UNITED STATES PATENT OFFICE INSTRUMENT FORDETERMININ G MOTOR VEHICLE ACTION Louis J. Fuller, Los Angeles, Calif.Application June 3, 1952, Serial N o. 291,440 9 Claims. (Cl. 235-61)This invention has to do with an instrument strument simple andinexpensive of manufacture for determining motor vehicle action and itis and simple and convenient to use. more particularly concerned with adevice or It is another object of this invention to prooperatedinstrument or machine that can be tions likely to result in errors ormere approximaoperated quickly and accurately to ascertain the l@ tions.

answer to most problems that arise concerning It is another object ofthis invention to provide motor vehicle actions or performance when veaninstrument of the general character referred hicles are involved inaccidents. to which is of such simple construction, and of Motorvehicles, such as automobiles, operated such simple character,generally, as to make posover modern highways are, from time to time,sible quick, accurate operations by persons uninvolved in accidentsfollowing which it is often skilled or untrained in the handling ofmathnecessary and highly desirable to ascertain with ematical problemsand who are ordinarily not reasonable accuracy an unknown or disputedfact qualified to solve problems or express opinions from aconsideration of known factors. In a in situations where several factorsare known typical and most usual situation a vehicle inand -a criticalfact is to be ascertained therefrom.

volved 1n an accident leaves a skid mail: of a The instrument providedby the present inmeasurable or known length on a pavement of vention 1scharacterized by two elongate, rigid known character and pitch Thefactor unmain scales connected by a coupling means so speed of thevehicle at the time the skid mark tionship. Markings or graduations onone main tions and then give an answer or opinion which a reference markcooperatively related to the is reasonably accurate. Such persons arenot markings occurring in the main scales, and it always available andit is not always possible to bears a series of marks or graduationsextending contact them. and therefore an unknown fact, lengthwise of itand from the reference mark such as I have referred to, may be thesubject of and representing factors, as for instance, friclengthy debateor controversy, or it may never tional characteristics of differentpavements or be ascertained with Suicient accuracy t0 make surfacings. Aslide, or scale coordinator cooperpossible a DrODer 0r equitableSOlutiOn 0f a 0011- ates with the several scales and is shiftable ortroversy. Itis, of course, obvious that the ascermovable lengthwise ofthe instrument and reltaining 0f a fact Such as the one menPonfd fromative to the scales. The slide bears an indicating factors such as tho,that I have pomteq out 1s 40 mark and a pitch indicating means isprovided on frequently the subiect of legal controversy and is one thatis Commonly Sought by persons en or is carried by the slide. The pitchindicating gaged in law enforcement and in the handling or .mealsmvolves a gra'vlty actuated element alnd settling of insurance Claimsyeta a series of graduations or markings with which It is an object ofthis invention to provide an Phe grajvlty actuated element cooperates S0that instrument of simple, practical form and which is 1f the mtrumenf?1S placed 0n a pavement the such that it can be easily and accuratelyoperated pltffh. @1f mclmatlon 0f the Pavement results in and whichinvolves scales representing factors posltlomng 0f the gravity actuatedelement so incidental to automobile performance and related Phat a 1"ejldng S ascertained whereby that factor so that with certain knownfactors available an 1S taken m130 account aS the instrument is read.

unknown fact can be accurately ascertained In a typical form 0f theinvention Pavement en- It is a general object of this invention toprogagmg elements 0r feet are provided on the vide an instrument of thegeneral character re- Structure, preferably at ODDOSB ends thereof,

ferred to which includes or requires but few yand when the feet are inoperating position they simple, relatively movable parts, making theindepend and are adapted t0 be engaged with the markings or graduationsI2.

acs/1,538

3 pavement, the pitch or inclination of which is to be determined.

The various objects and features of my invention will be fullyunderstood from the following detailed description of typical preferredforms and applications of the invention, throughout which descriptionreference is made to the accompanying drawings, in which:

Fig. 1 isa face view Aof the instrument :provided by the presentinvention, showing it unactuated or in a form in which it may be readilyhandled or stored. Fig. 2 is a view of the instrument on a scale reducedfrom that shown in Fig. 1, and showing the relatively movable `scales'extended and the feet of the instrument depending and in engagementwith a surface or pavement. 3 is a view illustrating the instrument in`a ty-pical setting or position in whichit occursv when it "j, ispositioned to be read, the pitch or ih'dination indicating element beingin a position indicating that the -surface of the pavement previously'engaged is of zero -pitch or inclination. Fig. 4 is a view similar toFig. 3 showing the instrument in a corresponding setting or positionVbut with the .pitch or inclination indicating element 4showing aYsubstantial inclination or :pitch from ya true horizontal. 1 Figy5 isan 4enlarged face view of a portion of the instrument showing the slide,being an enlargement :of -a portion of Fig. l. Fig. 6 is a detailedsectional view taken as indicated by line .B-B on Fig. g5. Fig. I? is adetailed `sectional view taken as rindie vted :by line 'I1- 1 von Fig.5. Fig. 8 is an enlarged view of one end of the i-nstrument as shown inFig. 1. Fig. r9 is an end view of the instrument, bbeing a view taken asindicated byline 9-9 on Fig. a8. l0 is a vview similar to Fig. :8showing :the foot occurring at `that end of the instrument Adown v.or inworking position. Fig. A1=1 is lanenlarged view of the end portion Iofthe instrument ,shown `at Athe right in Fig. 2, showing the foot shownvin the folded position indicated the down 4or working position. Fig. 12is an .end View, being ra view taken as indicated by line 1I2-I=2on'Fig. 1l and Fig. -13 4is a `reduced View similar to Fig. 5, form ofconstruction.

The instrument Vas provided by the .present iinvention includes,generally, two elongate main scales /A and B and a coupling `means `Crigidly iconnecting the main 'scales and rholding `them in 4spacedparallel relationship. An intermediate lor working scale 3D is providedand bccurs between Vthe -main scale A 'andB and la slide or scale'coordinator :E is provided fand y'is adapted to be operated 'lengthwiseof Ithe assembled scales =A, .1B and D. A pitch indicating means F isprovided and yis l-preferably :carried by the slide E. and in thepreferred construction pavement engaging feetG are provided at theendsof theinstrument.

showing another k The main scale A preferably involves va simple 60 AHlwhich is rigid and II bear-ing a series of A The markings or graduations.I2 r.preferably occur .on the lface -II adjacent nthe edge I3 Vwhichopposes scale Brand in the case illustrated they represent'values of 'aparticular factor, namely, distance. and vin practice itisconvenientthat they represent such values in terms of feet.

"The `main scale "B is similar, 'gene'ra'lly, lto 'the main scale A, inthatit has an elongate, straight, 4#rigid body I5 with a front face 'I6bearing a seriesof markingsor graduations -I1. Thelm'ark- `ings orgraduations If'I occur '`onface VI5 vadjacent l.the edge I- of tthescale vB opposing the scale JA.

straight, elongate body Awhich has a front face The graduations ormarkings I'I represent values of a particular factor, namely, speed, andin the case illustrated they represent this factor in terms of miles perhour. It is to be understood, of course, that if desired this factor canbe represented in terms of feet per second, or if desired both suchsystems of graduations can be incorporated simultaneously on the faceI6.

'The coupling means YYC connects the scales A Jand -B together in xedspaced parallel relationship, as shown throughout the drawings. In theparticular construction illustrated the means C includes spacedVcoupling plates 20 at each end of the assembly 'formed by the scales Aand B and these plates are connected or made fast to the 'end portionsof the scales A and B by suitable fasteners V2 I.

The 'intermediate or working scale D is cooperatively related to themain scales A and B and is preferably supported by and between the main-'sca-les -A `and B. In its preferred form the -scale D lhas -a simplestraight rigid body 2v-2 with a front vface v23 flush with `or in theplane of 'the faces I'I and -Ir6 of scales A and B, respectively. Thescale D is provided withor characterized by la Ytransverse referencemark 20 which `is prefervably such as to extend between the upper andlower edges 26 and 21, respectively, 'of the face 23 so that this markcan lbe readily positioned for accurate reading withreference to-the'fmark- A-ings I-'I on scale B.

-In accordance with the present invention the scale D is provided with'markings or .graduation's 28 in a series lrelated to or extendinglengthwise of the body 22 from thevreference mark 20 `and the samedirection to lthat in which the markings on the scales A and B progress.The markings 22B represent factors such Ias coefficients of fricftionand in the case illustrated the reference `mark 26 is ata .pointrelative to the lmarkings l28 `where it represents :100 percent, whereasthe :markings -28 represent Vcoefficients 'less fthan 100 percent, aswill be readily understood from 'an examination rof Fig. 1 offthedrawings.

'In employing the instrument provided by the present invention suitableA,preliminary tests can be made to ascertain exactly what coefficient of.friction factor is to beemployed when using the instrument, or forordinary .practical results it can 'be assumed that va particularpavement for surface that :is known and which is vinvolved in the-problem 'has a recognized or known coefficient of friction. Forexample, it 'is generally "recognized, and it has been ascertained byfex .perienceor test, that vthe coefficient of friction -to be employedif the pavement involved -is brick is 40%, if the `pavement involved 'isgravel it is 50%, if ythe pavement involved lis asphalt `-it "is '60%and if the 'pavement is 'conc'rete it 'is 70%. For convenient 'referenceit is preferred 'that 'a 'table of such factors `be 'provided 'on the'face 23 offscale B, as at 30.

In the preferred form of the invention fthe working scale D`is supportedvby or mounted 'belengthwise relative tothe scales AandB. In'th'e:particular -case illustrated the body '22 of scale D is provided Vatrits upper and lower edges with 1longitudinal ribs 'or rails `3'I "whichtare slidably (carried in grooves 32 provided in the opposing edges of'scalebodies I'Il and I5, respectively.

'Thescale coordinator orslide E is Vcarried by the'assembly of scales A,B and D and inthe form iillustrated'it, involves an `upper block 35, alower block f36. 1a back plate 31 and 'front plate 33.

These several parts are held in a rigid assembly by suitable fasteners33. The top or upper block 35 is slidably engaged with the top edge 4Dof the body I of scale A and in the case illustrated the block has a ribor rail 4l slidably carried in a groove 42 provided in the upper edge 40of the scale body I IJ. The block 36 occurs immediately below the loweredge 45 of the body I5 of scale B. A suitable drag or friction elementis provided between the block 36 and the scale body I5. In the caseillustrated this element is in the form of a drag or friction spring 48located or conned between the block 36 and the body l5 of scale B.

In accordance with the present; invention the front plate 38 of theslide E is transparent, or at least has a transparent portion, and atthat point an indicating mark 50 is provided, as clearly illustrated inFig. 5 of the drawings. The indicating mark extends transversely of theinstrument, that is, it is provided on the slide E so that it extendstransversely of the scales A, B and D, and it is of such extent as tooverlie the markings occurring on the scales A, B and D.

The pitch indicating means F in the form of the invention illustrated inFigs. 1 to l2, inclusive, is characterized by a gravity actuated elementin the form of a pendulum or pointer 6D. The pointer is located in asuitable cavity 6I provided in the inner side of the front plate 38 sothe cavity opposes the front faces il and 23 of the scales A and D,respectively. A pivot pin 62 is carried by the slide to extend throughthe upper portion of the cavity 6| and the pointer 68 is pivotallycarried by the pin 62. The axis o'l pin 62 is normal to the plane inwhich the faces Il, l5 and 23 occur.

In the construction illustrated a lock means is provided normallyholding the pointer against pivotal movement, and this means includes aspring 65 carried in the top block 35 of slide E and normally bearingagainst a flange 66 on the pivot pin 62 so that the flange 66 holds thepointer tight against the wall 6l of the cavity 6| The pivot pinprojects from the front plate 38 of slide E and is provided with anoperating knob 68. When the knob 68 is depressed the pressure on thepointer is released so that the pointer is moved by gravity into a trulyperpendicular position.

In accordance with the invention markings l0 are provided on the plate38 in series extending in each direction or from each side of theindicating mark 50, as clearly shown in Fig. 5 of the drawings, andthese markings l0 are preferably spaced to give readings of inclinationin terms or degrees or percentage, the markings to one side of theindicating mark indicating a minus or down grade inclination and thoseon the other side indicating a plus or up grade inclination.

The pavement engaging elements G provided by the invention arepreferably in the nature of feet provided at opposite ends of theinstrument, as hereinabove described. In the preferred form of theinvention there is a foot 80 at one end of the instrument, say, forinstance, at the lefthand end of the instrument where it is carried by apivot pin 8| supported by the end portion of the main scale B. The foot8U is operable between a normally collapsed or folded position such asshown in Figs. 1 and 8, where it lits close to or possibly partly aroundthe end portion of scale B, and a working or depending position such asis shown in Fig. 10, where it projects down and is Fig. 2 of thedrawings.

Through the construction just described the depending feet of theinstrument can be engaged with the surface S at points spaced asubstantial distance apart, with @e result that an accurate gradereading is obtained and the feet are of such extent as to support theinstrument in the manner shown in Fig. 2, with the slide E. spaced fromthe surface S to be clear thereof.

In the form of shown in Fig. 13

in the nature of a spirit level, there being liquid carried in anarcuate chamber provided in the front plate 38 of the slide and a bubbleoccurs in the liquid. It will be immediately apparent that gravity actson the liquid in the cavity 90 to locate the bubble in a manneranalogous to its operation on the pointer 60, as hereinabove described.

With the instrument provided by the present invention a number ofproblems can be readily, accurately and fully solved, as where two orthree factors are known and it is desired to ascertain a fact that canbe mathematically determined from those factors. In other cases theinstrument can be used to ascertain a factor that can be employed inmaking various calculations. No attempt will be made here to explain thenumerous manners in which the instrument can be operated in the solvingof problems or in ascertaining factors, since it is believed that thefollowing simple examples will serve as an adequate basis forunderstanding the invention.

In a typical situation, as, for instance, where there has been a usualtype of automobile accident, there is a skid mark of a particular lengthon a pavement at a particular location. It is possible and obviously avery simple matter to measure the length of the skid mark. The operatorof the present instrument may extend the feet of the instrument toworking position and if he so desires he may extend the scale D at asubstantial distance to the right relative to the scales A and B, andthen contact the pavement where the skid mark occurs with the feetplacing the instrument lengthwise of the skid mark and releasing thelock means of the pointer 6U. When the pointer is at rest the lock meansis allowed to engage, setting the pointer in a position corresponding tothe pitch or inclination of the pavement, as for example, in theposition shown in Fig. 4 of the drawings.

With the length of the operator of the instrument ing scale D to aposition where the reference mark 20 comes opposite the reading on thescale A corresponding to the length of the skid mark. The character ofthe pavement is of course readily ascertainable as by observation, andthe operator of the instrument with this fact known moves the slide Erelative to the scale D until the marking on the slide E designated bythe pointer E0 is in register with the marking 28 occurring on scale Dand designating the coefli` skid mark known, the then moves the workthepitch indicating means of the drawings the gravity answer; namely, whenthe skid mark startedwas 45 miles per cient of friction factorcorresponding to'such suriface. As for example, if the surface of thepave ment is asphalt the mark designated on the slide E iS moved intoregister with the mark designated 60 on the scale D. The mark indicatedor desigv nated on scale E, as by the pointer 60 when thus registeredwith the proper marking on scale: D is read with reference tothemarkings il on scale B. giving the operator a reading in speed ormiles per hour at which the vehicle was moving when the skid markstarted.

In another case, for example, it may be assumed that the skid markoccurring on a level pavement of asphalt is 112.5 feet long. Theoperator in this case will rst set scale D so that the reference mark 25is at 112.5 on` scale A. He will then move the slide E to bring theindicating mark 50 on thel slide E in register with the mark 60occurring on slide D, whereupon the mark 50 read on scale B gives thethat the speed of the vehicle hour.

As an example of another manner in which the instrument may be operated,it may be assumed that the speed of the vehicle is i5 miles per hour,thatthe pavement is asphalt and level, and it is desired to know howlong the skid mark will be in such a situation. In this case theoperator of the instrument may set the slide E with the indicating mark50 at 45 on scale B and then position scale D with marking 50 inregister with the indicating mark 50, whereupon the reference mark 25will readl at 112.5 on scale A, thus giving the length of the skid markas 112.5 reet.

Itis, of course, to be understood that in carrying outthe presentinvention the series of markings provided on the scales are related orso laid out as to represent values on a basis or in such relationship asto give the answer to problems worked as above pointed out.

From the foregoing description it will be apparent that the instrumentas provided by the present invention is simple oi construction andoperation, thatl assuming the instrument has been constructed with thescales accurately related, the readingsy obtainable are accurate. it isto be observed that the folding feet provided on the instrument makepossible convenient handling or'storage of the instrument and it isnotable that the pitch indicating means, when employed, serves, ineiect, to take into account or make correction for pitch ofv thepavement.

I- I-avingY described only typical preferred forms and applications ofmy invention, I do not wish tobe limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any variationsor modifications that may ap-i pear to those skilled in the art and fallwithin the scope of the following claims,

Having described my invention, I claim:

1. An instrument of the character described including, two straightrigid elongate scales with bodies established in spaced parallelrelationship, one a main scale having markings in an elongate series andrepresenting values oi distance and the other a :nain scale havingmarkingsin an elongate series and representing values of speed anelongate rigid working scale with a body slidable between the mainscales and parallel therewith and having markings in an elon gate seriesand including a reference mark co operatively related to the markings onthe main scales and having markings in a series longitudie nal of theworking scale and representing values of friction coefficient, and aslide :movable longitudinally relative to said scales and having anindicating mark cooperatively related to the markings on each of saidscales and having mark ings in a series extending from the indicatingmark lengthwise of the scales and representing values of a factormodifying the` coefficient of friction.

2. An instrument of the character described including, two straightrigid elongate scales with bodies established in spaced parallelrelationship, one a main scale having markings in an elongate seriesandl representing values of dis tance and the other a main scale havingmarkings in an elongate series and representing values of speed, anelongate rigid working scale with a body slidable between the mainscales and paral= lel therewith and having markings in an elon gateseries and including a reference mark cooperatively related to themarkings on thev main scales and having markings in a series l'ongitudi'nal of the` working scale and representing values of frictioncoeiiiicient, and a slide movable lon gitudinally relativeto said scalesand having an indicating mark cooperatively related toA the markings oneach or said scales and having mark,- ings in series extendinglengthwise oi the scales inboth directions from the indicating mark andrepresenting values of variation from a horizontal plane.

3. An instrument of the character described including, two straightrigid elongate scales with bodies established in spaced parallelrelationship, one a main scale having markings in an elongate series andrepresenting values of dis-V tance and the other a main scalehavingmark.- ings in an elongate series and representing values of speed, anelongate rigid working scale with a body slidable between; the mainscales and. parallel therewith and having markings in an elongate seriesand including a reference mark cooperatively related to the markings onthe main scales and having markings in a series longi'.- tudinal of theworking scale and representing values of friction coefficient, a slidemovable longitudinally relative to the scales. and having an indicatingmark cooperatively related to the markings on eachk of thev scales, andpitch indieating means including markings in a series extendinglongitudinally or" the scales and from the indicating mark and a gravityactuated element carried bythe slide and cooperatively related to thelast mentioned markings.

4 An instrument or the character described including, two4 straightrigid elongate scales with bodies established in spaced parallelrelationship, one a main scale having markings in an elongate seriesandY representing values of disw tance and the other a main scale.having markingsin an elongate series and representing values of speed,an elongate rigid working scale with, a bodyslidable between the; mainscales and parallel therewith and having markings in an .elongate seriesand including a reference mark cooperatively related tothe markings onther main scales and having markings in a series lungitudinal or theworking scale and representing values of friction coefficient, a slidemovable longitudinally relative. to the scales and having ,an indicatingmark cooperatively related to. the markings on each of the scales, andpitch indicating means including markings in a series ex-A tendinglongitudinally of the scales andk from the indicating mark and: agravity actuated pivotally mounted indicator carried by the slide andcooperatively related to ings.

5. An instrument of the character described including, two straightrigid elongate scales with bodies established in spaced parallelrelationship, one a main scale having markings in an elongate series andrepresenting values of distance and the other a main scale havingniarkings in an elongate series and representing Values of speed, anelongate rigid working scale with body slidable between the main scalesand parallel therewith and having markings in an elongate series andincluding a reference niark cooperatively related to the markings on themain scales and having markings in a series longitudinal of the workingscale and representing values of friction coeiicient, a slide movablelongitudinally relative to the scales and having an indicating markcooperatively related to the markings on each of the scales, and pitchindicating means including markings in a series extending longitudinallyof the scales and from the indicating mark, a gravity actuated pivotallymounted indicator carried by the slide and cooperatively related to thelast mentioned markings, and re leasable lock means normally holding theindicator against movement relative to the slide.

6. An instrument of the character described including, two straightrigid elongate scales with bodies established in spaced parallelrelationship, one a main scale having markings in an elongate series andrepresenting values or distance and the other a main scale havingmarkings in an elongate series and representing values of speed, anelongate rigid working scale with a body slidable between the mainscales and parallel therewith and having markings in an elongate seriesand including a reference mark cooperatively related to the markings onthe main scales and having markings in a series longitudinal of theworking scale and representing values of friction coeilicient, a slidemovable longitudinally relative to the scales and having an indicatingmark cooperatively related to the markings on each of the last mentionedmarkthe scales, and pitch indicating means including markings in aseries extending longitudinally of the scales and from the indicatingmark and a gravity actuated means including a body of fluid in anarcuate chamber and carrying a bubble cooperatively related to the lastmentioned markings.

'7. An instrument of the character described including, two straightrigid elongate scales with bodies established in spaced parallelrelationship,

one a main scale having markings in an elongate series and representingvalues or distance and the other a main scale having markings in anelongate series and representing values of speed, an elongate rigidworking scale with a body slidable between the main scales and paralleltherewith and having markings in an elongate series and including areference mark cooperatively related to the markings on the main scalesand having markings in a series longitudinal of the working scale andrepresenting values of friction coeilicient, a slide movablelongitudinally relative to the scales and having an indicating markcooperatively related to the markings on each of the scales, and pitchindicating means including markings in a series extending longitudinallyof the scales and from the indicating mark, a gravity actuated elementcarried by the slide and cooperatively related to the last mentionedmarkings, and feet on the assembly of scales and spaced apart andadapted to engage the surface of a pavement.

8. An instrument of the character described including, two straightrigid elongate scales with bodies established in spaced parallelrelationship, one a main scale having markings in an elongate series andrepresenting values of distance and the other a main scale havingmarkings in an elongate series and representing values of speed, anelongate rigid working scale with a body slidable between the mainscales and parallel therewith and having markings in an elongate seriesand including a reference mark cooperatively related to the markings onthe main scales and having markings in a series longitudinal of theworking scale and representing values of friction coefficient, a slidemovable longitudinally relative to the scales and having an indicatingmark cooperatively related to the markings on each of the scales, andpitch indicating means including markings in a series extendinglongitudinally of the scales and from the indicating mark, a gravityactuated element carried by the slide and cooperat1vely related to thelast mentioned markings, and feet on the assembly of scales and spacedapart and adapted to engage the surface of a pavement, one foot beingcarried by the combined main scales at one end of the assembly of scalesand the other foot being carried by the working scale at the other endof the assembly of scales.

9. An instrument of the character described including, two straightrigid elongate scales with established in spaced parallel relationship,one a main scale having markings in an elongate series and representingvalues of distance and the other a main scale having markings in anadapted to engage the surface of a pavement.

LOUIS J. FULLER.

References Cited in the le of this patent UNITED STATES PATENTS byPurdue University of Lafayette, Indiana, in 1933, as Bulletin No. 32 ofthe Engineering Extension Department, pages 19-31.

